As we see in this answer, DISCO is a sub-service for discovering the WSDL URL for a given SOAP service.
Indeed, when we examine the HTML source of the Help page returned by a WCF service, we can see the DISCO URL:
<head>
<link rel="alternate" type="text/xml" href="https://example.com/service?disco" />
...
</head>
When we follow that link with an old net48 service, we get a well-formed XML response that contains the correct WSDL URL.
Not so with CoreWCF, however, at least in its default implementation.
Instead, we get:
An ExceptionDetail, likely created by IncludeExceptionDetailInFaults=true, whose value is:
System.InvalidOperationException: Token StartDocument in state Document would result in an invalid XML document.
at System.Xml.XmlWellFormedWriter.ThrowInvalidStateTransition(Token token, State currentState)
at System.Xml.XmlWellFormedWriter.AdvanceState(Token token)
at System.Xml.XmlWellFormedWriter.WriteStartDocumentImpl(XmlStandalone standalone)
at CoreWCF.Description.ServiceMetadataExtension.HttpGetImpl.DiscoResult.Write(XmlWriter writer)
at CoreWCF.Description.ServiceMetadataExtension.HttpGetImpl.MetadataResult.WriteResponseAsync(HttpResponse response)
at CoreWCF.Description.ServiceMetadataExtension.HttpGetImpl.TryHandleMetadataRequestAsync(HttpContext requestContext, IQueryCollection queries)
at CoreWCF.Description.ServiceMetadataExtension.HttpGetImpl.ProcessHttpRequest(HttpContext requestContext)
at CoreWCF.Description.ServiceMetadataExtension.HttpGetImpl.HandleRequest(HttpContext httpContext)
Is there a way to turn on DISCO in CoreWCF, so that a consuming client can get the WSDL URL? The documentation doesn't seem to address this problem (unless I missed it, which I don't think I did).
